Flicker attachment for photometers.



. E. F. KINGSBURY. FLICKER ATTACHMENT FOR PHOTOMETERS. APPLICATION FILED IuIIE I. I9I5.

1,176,466. I Patented Mar. 21,1916.

Ma/A

THE COLUMBIA PLAryouRAPH co. WASHINGTON, D. c.

.man srarns rarnnr ernten..

EDWIN F. KINGrSIBURY, OF COLWYN, PENNSYLVANIA, ASSIGNOR TO THE UNITED GAS IMPROVEMENT COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATON OF PENNSYLVANIA.

Specification of Letters Patent.

Fatented Mar. 21, 1916.

Application filed .T une 7, 1915. Serial No. 32,539.

To all whom it may concern.'

Be it known that I, EDWIN F. KINGSBURY, a citizen of the United States, residing at Colwyn, Delaware county, Pennsylvania, have invented a certain'new and useful Flicker Attachment for Photometers, of4

which the following is a specification.

' An equality of brightness photometer is extensively and satisfactorily used where the color of the sources of light is substantially the same. However, where the color of the sources of light is dilerenha flicker photometer is most appropriate. Although these ,instruments have many parts in commen, it has been customary to construct them `as separate instruments throughout so that the custom has been to provide and employ two complete photometers, one of the flicker' variety `and the other of the equality of brightness variety, and this entails considerable expense, trouble and annoyance.

The principal object of the present invention is toprovide for economically making one type of photometer do the work of two and operate either by equality of brightness or by the iicker method as may be required.

Another object of the invention is to provide a iicker attachment which shall be comparatively inexpensive and efficient and which can be conveniently interchanged with the telescope of an 'equality of brightness photometer and which, when so interchanged, converts the device into a flicker photometer.

The invention will be claimed at the end hereof but will be first described in connection with the embodiment of it in a Lummer- Brodhun contrast photometer, although it can be embodied in other types of well known photometers, the Lummer-Brodhun type being selected merely for illustration in the accompanying drawings in which- Figure 1, is a perspective view of so much of a Lummer-Brodhun contrast photometer as is necessary to illustrate the application of my invention thereto. Fig. 2, is a transverse sectional view illustrating a flicker attachment embodying features of the invention. Fig. 3, is a diagrammatic sectional plan of the photometer proper. Fig. 4, is a diagram of the Lummer-Brodhun contrast photometer field, showing also the method by which the flicker attachment utilizes the same, and Fig. 5, is a view similar to Fig. 4,

but showing another type of equality of brightness photometer field.

Although l shall describe the invention in connection with the Lummer-Erodhun type ofcontrast photometer, the invention is not limited to that type as there are other well known types of equality of brightness photometers to which itis applicable.

In the drawings 1, is a tube adapted to replace and to be interchangeable with the ordinary telescope of an equality of brightness photometer. At one end of this tube there is arranged a magnifying lens 2, and at the other end the lens 3, of the eye-piece. The lens 2, is mounted in the carrier inserted inthe end of the tube 1, and the lens 3, is mounted in one end of a second tube 4, inserted in the first tube 1, and constituting in elfect a continuation thereof. T he prism 5, is mounted in a spool-like structure 6, revolubly mounted in a ring bearing 7 arranged within the tube 1, and held to place by a set screw 8.

9, is an oil hole.

The flanges of the spool-like structure 6, operate as collars and prevent end play of the structure in its bearing ring while permitting the structure to rotate freely.

10, is a belt advantageously of the coiled wire or spring variety and it connects the pulley 11, on the structure 6, with the pulley 12, of amotor 13, shown as of the electric variety. A

. 14, is a spring brake armcarried by a bracket 15, and adapted to be made to press upon the pulley 12, or some part thereof, with more or less pressure by means of the adjusting screw 16, carried by the bracket 15, so as to afford control of the speed of the motor and of the speed of rotation of the prism.

`17, is a centrally apertured disk or partition arranged at the inner end of the tube 4.

Mounted on the tube 4, so as to be turnable thereon is a lighting fixture 1S, consisting of a collar encircling` the tube and an open ended chamber 19. in which the lamp or light is arranged. There is an opening 20, in the tube 4, the effective size of which can be varied by turning the fixture 18. and in this way the extent or degree to which the interior of the eye-piece is illuminated can be varied. The function 0f the lighting fixture is to supply, as shown from an electric lamp, light for the purpose of illuminating the Whitened interior of the tube 4, and more particularly the surface of the partition or disk 17, nearest the eye so as to avoid excessive strain on the eye such as would occur if the surface Were dark and.

.contrast photometer, the box 2l, of which is provided with an opening 22, that detachably receives the described attachment and that received the ordinary telescope which is not shown but is Well understood. The arroivs 23 and 24, indicate rays of light from kthe respective sourcesin their passage through the box and in respect to the reflecting surfaces thereof and to the device 25. bv which thev are brought into juxtaposition. To apply the attachment of mv invention to the box 2l, the telescope and its contrast glasses are removed and the attachment applied in the manner described and when so applied it is evident that there is provided a liicker photometer in cnnection with which the ordinary box 2l.v and its accessories are utilized.

Referring to Fig. 4, 2G, indicates the-*field of light presented to the eye by one sf-urce of light, and 27, represents the field of light presented to the eve by the other source of light; This is the condition of aliairs When the flicker attachment is not present. Then-the attachment is in operation the field presents nothing but a small illuminated circle which travels in a circular orbit 29. As the prism revolves. the circular field 28, travels around in its circular orbit 29, and its brilliancy and color vary as it travels.v orin other Words,A itrflickers untilv the brillianc'y of those portions of the fields of light 26 and 27, traversed bvthe circle be- 'come equal whereupon the field 28, ceases to flicker and has but one color.`

The cfnstruction and mode of operation of the arrangement shown inv Fig. 5, is the saine as in Fig'. 4, except that thelields 2,6a and 27a, are ot different shane.

It Will be obvious to thoseskilled in the art to which theinvention relates that modications may be made in details of con-V struction and arrangement Without departing from the spirit of the.Vini/ enti.QnY Which is not limited as to those mattersfnor t'urther than the appended claims and the prior state ofthe art may require.

What 'I claim is:

LA flickerV attachment for'equality otV brightness Aphotometers which consists of a sight tube interchangeable With the telescope of such photometers and provided with lenses and a, rotary prism and an apertured diaphragm and adapted for detachable application to such photometers, substantially as described. Y

2. A flicker attachment for eopualityV of brightness photometers consisting :of the combination of atube having a lateralopening, a prism revolubly mounted inthetube7 lenses and an apertured diaphragm mounted in the tube, and a ligl'iting fixture rev? olubly mounted Pn the tubeand provided with a` lightiand an onen ended lighting chamber which can be brought intok Vvarying alinement with said lateral "opening, suhstantiallyl as described.

3. The combination of l anequality Y of brightness,photcmeter, a detachable sight tube having prism., arranged therein, and means for rotating.vv the prism,y substantially as described. Y Y j 4. The combination of an eoualitv of brightness photometer and a detachable sight tube having al prism revolu'bly mount-` ed therein.

5.The combination ofan equality of brightness photo-meter, a detachable sight tube having a prism revolubly mounted therein, a` motor, a` spring beltl between theV mctor and prism, a. brake for the motor, and a set screvvfor adiusting the brakeLsub.- stantiallv as described. 'Y

6, A flicker attachment forequality of bri ghtness'photometers consisting of a sieht tube, a, ring mounted therein, a spool-like structure revolubly mounted in thering and provided with a prism, and lenses and an apertured diaphragm mounted in Saidl tube, substantially as described.

EDWIN F. KINGSBURY. Witnesses: Y

0. B. EVANS, GEO.- W. Mlaervs..

Copies of this patent may. be obtained foi` five cents each, by.addressixig'A the Commissioner of 1 atents,

VTasiingtonz D, C, 

